Automatic electron time-switches



Oct. 24, 1967 R. PEFFER 3,349,293 AUTOMATIC ELECTRON TIME-SWITCHES FiledMarch 16, 1965 2 Sheets-Sheet 1 a m mx Qy/h 0 Q6 "2' mwd fab Oct. Z4,1967 R. PEFFER 3,349,293

AUTOMATIC ELECTRON TIME SWITCHES Filed March 16, 1965 2 Sheets-Sheet zUnited States Patent 5 Claims. (cl. 317-142 Automatic time-switchesmounted in electrical networks consist as a rule of electromechanicaldevices, mostly rather noisy, of which the time-lag is adjustable onlywithin relatively narrow limits. Heat-responsive time switches are alsoknown, but to operate them the user must depress the control knob duringa relatively long time period, at least one second. Moreover, theirtimelag characteristic is subordinate to the room temperature and theuseful life of their heat-resisting element is rather short.

It is the essential object of this invention to provide an automatictime-switch free of the various drawbacks set forth hereinabove whichcharacterize conventional time-switches.

To this end, the invention provides an automatic electron timeswitchcomprising a main relay of which the energisation is controlled bydepressing the control knob, and a time-lag system of which theenergisation is controlled in turn by said relay, this automatictime-switch being characterized in that the main relay is of thesocalled step-by-step type having two stable positions, and that itscontacts control on the one hand the passage and the breaking of theload current and on the other hand the energisation of the tirne-lagdevice of which the circuit comprises a condenser having connected inparallel across its terminals a branch circuit comprising a gasfilledlamp and the winding of a secondary relay controlling the closing of aconductor adapted likewise to energise the main relay.

Four typical forms of embodiment of the automatic electron time-switchaccording to this invention are described hereinafter by way of examplewith reference to the attached drawings, in which:

FIGURES 1 to 4 are wiring diagrams corresponding each to one of thesefour form of embodiment.

The automatic electron time-switch illustrated in FIG- URE 1 comprises amain replay RP of a special type, that is, a step-by-step controlledpulse relay of which the main contact RP has two stable positions. Thus,each time the coil of this relay is energised, the main contact RP movesto the other position; in other words, it closes if it was open andopens if it was closed. In the inoperative or de-energised position thismain contact is normally open. The coil of this main relay may beenergised from a suitable mains distributor designated by the referenceletters DI, for example a 110-volt A.C. mains.

This relay controls the supply of current to a load circuit U as well asto a time-lag device comprising a condenser C having connected inparallel across it terminals a branch circuit comprising a gas-filledlamp L and the winding of a secondary relay RX adapted to control theopening of the time-switch circuit.

To simplify the description, the diagram may be divided into four mainsections.

I.-The control circuit of main relay RP,

II.The charging circuit of condenser C in the time-lag device,

III.The discharge circuit of this condenser C, and

IV.The load circuit proper U.

The charging circuit of condenser C and the discharge circuit thereofconstitute somewhat the complete circuit ice of the automatic time-lagdevice, which is designated as a whole by the reference numeral 5.

I.-The control circuit of the main relay RP comprises a push-button BPmounted in parallel with the contact RX of an auxiliary relay, thisassembly being connected in series with the coil of the main relay RP.The two ends of this control circuit are designated by the letters A andB, the end A (on the push-button side) being connected through aconductor 1 to the mains terminal F while the other end B (coil side) isconnected through another conductor 2 to the mains terminal G.

Of course, if the case contemplated is that of a timeswitch installationadapted to be operated from several points, a corresponding number ofcontrol push-buttons may be connected in parallel.

II.-The charging circuit of condenser C consists of a resistance Rconnected in series with the condenser C. The charging current iscontrolled directly by the value of this resistance R which maytherefore be variable in order to increase the range of permissibleadjustment.

The assembly consisting of condenser C and resistance R is connected inparallel with a resistance R connected in series with a potentiometer Pand a rectifying cell S. A switch T permits of opening the chargingcircuit, if necessary.

The end E of this circuit (on the switch side) is connected to thesupply terminal F.

The other end of this circuit, which consists of a conductor 10, isconnected to the other mains terminal (terminal G) through the maincontact RP of main relay RP, and through conductors 3 and 2.

The function of potentiometer P is to adjust the potential dilferenceacross the terminal of resistance R and therefore the charging currentflowing through resistance R III.The discharge circuit comprises, inparallel with condenser C, a conductor 7 in which a gas-filled lamp(neon tube) L and the coil of auxiliary relay RX are inserted.

This condenser may also be discharged through the medium of anotherconductor 9 comprising a contact RP and connected in parallel tocondenser C.

Contact RP (which is one of the contacts of the main relay RP) is atransient contact closing only when the coil of the main relay RF isenergised.

1V.-The load circuit U is connected in parallel to the charging circuitof condenser C. In fact, the terminal 4 of circuit U is connected to themains terminal G through conductor 10, contact RP and conductor 2, theother terminal 6 of this circuit U being connected to the other terminalF.

This time-switch operates as follows:

Assuming that the time-switch is properly connected to an electric mainsand that switch T is closed, the timeswitch is operated by depressing,even for a very short time, the push-button BP, thus energising the coilof main relay RP. As a consequence, the contact RP of this relay, whichwas open, will close and cause on the one hand the energisation of theload circuit U and on the other hand the charging of the time-lagcircuit 5 comprising the resistances and condenser C.

At the end of the time period for which the time-switch was previouslyadjusted by means of the potentiometer P, the voltage across theterminals of condenser C is suflicient to ignite the neon tube L whichbecomes conducting. As a consequence, the coil of main relay RP isenergised and the main contact RP of this relay moves from its precedingclosed position to its open position, thus discontinuing on the one handthe energisation of the time-lag circuit 5.

At the same time the transient contact RP of main relay RP has closedand short-circuited the condenser C so as to eliminate any residualcharge therefrom.

In the operation described hereinabove a single depression ofpush-button BP causes the energisation of the load circuit during thepredetermined time period for which the automatic time-switch wasadjusted.

This time-lag may be adjusted at will by means of the potentiometer P.The resistance R inserted in the circuit 5 may be of an adjustable type,so that several ranges of time-lag values may be obtained. Otherresistances may also be inserted in the supply circuit in order to adaptthe device to the mains voltage.

It may be noted that if during the operation of the automatictime-switch, as the time-lag period is elapsing, the push-button BP weredepressed again at any moment, the main relay RP would be energisedprematurely, this involving the opening of the load circuit U before thepreselected time period has elapsed.

Under these conditions, the user can reduce by a voluntary act thetime-lag period without interfering in any manner with the time-switchadjustment and without adding any complementary element to theinstallation, since the circuit is open by depressing the same button asthat used for closing it.

The automatic electron time-switch according to this invention isadvantageous in that its operation is reliable and noiseless, and itswear is reduced practically to zero. Moreover, this automatictime-switch permits of operating the installation as a remote switchingcontrol, without any modification, since it is sufficient to depress thecontrol push-button another time for breaking the load circuit beforethe predetermined time-lag of the time-switch has elapsed. The timeperiod already elapsed during the first portion of the cycle iseliminated and is in no way deducted from the time-lag period of thenext cycle.

On the other hand, by opening the switch T the user may neutralise thetiming system. In this case a first pressure exerted on the push-buttonBP will energise the coil of relay RP and therefore the load circuit Uas long as this push-button is not depressed again. This seconddepression, when exerted, causes the contact RP of the main relay tomove from its closed position to its open position,

whereby a real remote control of the load circuit U is obtained.

By way of example, in a specific form of embodiment the following valuesmay be selected for the various component elements of the automaticelectron time-switch of this invention:

C-6 ,ufarad/ O-volt paper condenser,

R 2.2 to 70-megohm resistance, R -4.3-megohrn resistance,

P-2-megohm linear potentiometer, RP-Step-by-step, S-volt-ampere mainrelay, RX10,000-ohm/ l-milliampere auxiliary relay, L-3 to S-milliampereoutput neon tube.

sumption is extremely low, of the order of 150 microamperes.

FIGURE 2 illustrates a modified diagram of the arrangement of FIGURE 1.In this alternate form of embodiment the transient discharge contact RPis replaced by a contact RP associated with the contact RP these twocontacts constituting a double reversing contact. This contact RP istherefore a back contact and has the same '4 function as contact RPHowever, with this arrangement the construction of the main relay RPissimplified.

FIGURE 3 illustrates the diagram of a thirdform of embodiment of theautomatic time-switch according to the present invention, which is sodesigned that depressing the push-button BP during a cycle of operationof the switch cannot break the load circuit U, as contrasted with thepreceding forms of embodiment of FIGURES 1 and 2.

In fact, for certain applications, notably in the case of an automatictime-switch controlling the lighting system in a house, it is necessaryto avoid opening the supply circuit during a cycle of operation, forexample in case the push-button were depressed by another user.

The general arrangement of this third form of embodiment of theautomatic time-switch according to this invention is similar to thepreceding one. Therefore, its circuit is nearly the same and thecomponent elements, approximately identical with those provided in thefirst form of embodiment, are designated by the same reference symbolsin the drawing.

As in the preceding case the main relay RP comprises a double reversingcontact RP RP However, this relay also comprises an auxiliary backcontact RP inserted in the conductor 8 also comprising the push-buttonBP.

Thus, when this contact is open, it prevents the depression of thispush-button from controlling the operation of relay RP. Under theseconditions during the operating time of the automatic time-switch it isnot possible to cause another operation of relay RP and therefore todiscontinue the supply of current to the load circuit U by re-actuatingthe push-button.

Thus, the automatic time-switch is released only through the time-lagsystem. However, when the timeswitch is released, depressing thepush-button will normally cause its resetting, for the auxiliary contactRP, is then closed. On the other hand, in this specific form ofembodiment the switch T is dispensed with, since it has no usefulfunction.

In certain applications, for instance in the case of an automatictime-switch controlling a lighting installation in staircases, it isadvantageous to have the possibility of resetting the time-switch atwill before its load or lighting circuit opens at the end of thepredetermined time-lag. It is also desirable that this resetting takesplace in this case without opening the load circuit beforehand, as wouldoccur in the case of the diagram shown in FIGURE 1.

FIGURE 4 illustrates the diagram of an automatic time-switch comprisingthe same component elements as the preceding forms of embodiment, but sodesigned as to provide the advantageous features set forth hereinabove.

This diagram may be compared with the diagram of FIGURE 1.

However, the main relay RP comprises, in addition to the main contact RPa double reversing contact T 2T3. In the latter, contact T2 is a backcontact (closed in the de-energised condition) and contact T3 is a frontcontact (that is, closing when the relay is energised). These twocontacts have a common point H connected to the control push-button BP.

' On the other hand, contact T3 is connected through a conductor 9a to apoint D common to resistance R condenser C and gas discharge lamp L. Asto contact T2, it is connected on the other hand to the winding of themain relay RP.

A specific feature of this diagram lies in the fact that the end pointsA and B of the control circuit of main relay RP are connected theopposite way with respect to the connections of FIGURE 1. Thus, point Ais connected to the mains terminal G through conductor 2, and point B isconnected to the mains terminal F through conduct-or 1.

This automatic time-switch operates as follows:

By depressing the control push-button BP the user causes the coil ofmain relay RP to be energised, since contact T2 is closed in thede-energised condition (back contact). Therefore, this relay operatesand closes the main contact RP while opening the first auxiliary contactT2 and closing the second auxiliary contact T3.

The closing of main contact RP will energise on the one hand the loadcircuit U and the circuit 5 of the timelag system.

After a predetermined time period the voltage across the terminals ofcondenser C is sufiicient to ignite the neon tube L, thus causing theoperation of the auxiliary relay RX and therefore the energisation ofthe coil of the main relay RP.

This last-named relay RP is thus operated to control the opening of itsmain contact RP as well as of its auxiliary contact T3, while closingthe other auxiliary contact T2.

Thus, the supply of current to the load circuit and to the time-lagcircuit is discontinued. On the other hand, the various contacts of therelays resume their initial positions, whereby the automatic time-switchis ready to 0perate again.

However, if during the operation of this automatic time-switch thepush-button BP were depressed again, this would not cause the main relayRP to operate again and break the supply of current to the load circuit.In fact, the auxiliary contact T2 inserted in conductor 1 is then open.

On the other hand, depressing the push-button BP will cause current toflow through the conductor 9a since the auxiliary contact T3 was closed.This causes the condenser C of the time-lag device to beshort-circuited.

As a consequence, the time period having already elapsed during thepresent cycle of operation is somewhat cancelled. Thus, the time-lagperiod commences again from the moment the redepressed push-button BP isreleased. In fact, the current continues to flow without break throughthe time-lag circuit, since the main contact RP, remained constantlyclosed.

Under these conditions, it is clear that with the wiring diagram ofFIGURE 4 the repeated depression of pushbutton BP cannot produce amomentary break in the load circuit, this constituting a very importantfeature.

Moreover, depressing the push-button BP during the operation of thesystem does not actuate any relay in the automatic time-switch, thusassisting in ensuring the noiseless operation of this device.

On the other hand, if the control push-button were jammed for anyreason, the coil of the main relay RP would remain de-energised duringthe entire time-lag period, as contrasted with the mode of operationobtaining with the forms of embodiment illustrated in FIGURES 1 and 2.

Finally, it will be readily understood by anybody conversant with theart that the automatic time-switch according to this invention may beused to advantage in many different applications, and should not beconstrued as applying only to the specific case of lighting systems,comprising a series of control push-buttons,

What I claim is:

1. Automatic electron time-switch comprising a main relay of which theenergis'ation is controlled by depressing a push-button, and a time-lagsystem of which the energisation is also controlled by means of saidrelay, said main relay being of the so-called step-by-step type havingtwo stable positions and controlling by means of its contacts on the onehand the passage and break of current to the load circuit and on theother hand the application of voltage to the time-lag system, thistime-lag system comprising a condenser having connected across itsterminals a branch circuit comprising a gas-filled lamp and the Windingof a secondary relay controlling the closing of a conductor also adaptedto supply energising current to said main relay.

2. Automatic electron time-switch according to claim 1, in which saidmain relay comprises a front contact inserted in a conductor connectingone of the terminals of the mains on the one hand to said load circuitand on the other hand to the circuit of said time-lag system, said mainrelay also comprising a secondary contact of the transient closing typewhich is inserted in a conductor adapted to short-circuit the condenserof said time-lag system.

3. Automatic electron time-switch according to claim 1, in which saidmain relay comprises a double reversing contact, one contact being afront contact inserted in a conductor connecting one of the mainsterminals on the one hand to the load circuit and on the other hand tothe circuit of the time-lag system, the other contact being a backcontact inserted in a conductor adapted to short-circuit the condenserof said time-lag system.

4. Automatic electron time-switch according to claim 3, in which saidmain relay comprises, in addition to said double reversing contact, anauxiliary contact which is a back contact inserted in the conductor inwhich said control push-button is inserted.

5. Automatic electron time-switch according to claim 1, in which saidmain relay comprises a main front contact inserted in a conductorconnecting one of the mains terminals on the one hand to the loadcircuit and on the other hand to the circuit of the time-lag system,said main relay further comprising a double reversing contact of whichthe back contact is inserted in the conductor comprising said controlpush-button, the front contact being inserted in a conductor adapted toshort-circuit the condenser of the time-lag system when said push-buttonis de pressed.

References Cited UNITED STATES PATENTS 2,433,254 12/1947 Aiken 317l422,453,486 11/1948 Ball 3l7-l42 2,889,495 6/1959 Farmer 3 l7l42 2,965,81412/1960 Gartner 3l 7.-l42,

MILTON O. HIRSHFIELD, Primary Examiner, L. T. I-IIX, Assistant Examiner,

1. AUTOMATIC ELECTRON TIME-SWITCH COMPRISING A MAIN RELAY OF WHICH THEENERGISATION IS CONTROLLED BY DEPRESSING A PUSH-BUTTON, AND A TIME-LAGSYSTEM OF WHICH THE ENERGISATION IS ALSO CONTROLLED BY MEANS OF SAIDRELAY, SAID MAIN RELAY BEING OF THE SO-CALLED STEP-BY-STEP TYPE HAVINGTWO STABLE POSITIONS AND CONTROLLING BY MEANS OF ITS CONTACTS ON THE ONEHAND THE PASSAGE AND BREAK OF CURRENT TO THE LOAD CIRCUIT AND ON THEOTHER HAND THE APPLICATION OF VOLTAGE TO THE TIME-LAG SYSTEM, THISTIME-LAG SYSTEM COMPRISING A CONDENSER HAVING CONNECTED ACROSS ITSTERMINALS A BRANCH CIRCUIT COMPRISING A GAS-FILLED LAMP AND THE WINDINGOF A SECONDARY RELAY CONTROLLING THE CLOSING OF A CONDUCTOR ALSO ADAPTEDTO SUPPLY ENERGISING CURRENT TO SAID MAIN RELAY.